Brake repair is, generally speaking, not a job for the amateur. Your brakes are the single most important safety feature on your automobile, and you cannot afford to take chances with homemade, and possibly badly-done, repairs. If you are experiencing problems with your brakes, a qualified mechanic should be your first stop. However, it is quite possible for you to maintain and check your brakes with just a small amount of knowledge and skill, and this twice-yearly check can save you money and frustration by detecting problems before they become major. If you notice a problem with your brakes, make a trip to the mechanic and have the problem addressed; you will probably save a good bit of money by early detection and repair. If brake problems are allowed to go unsolved, major and expensive repairs may be required, or you may place yourself in an unsafe driving situation.
You do not need any special tools to check your brake pads and discs beyond a ruler, a flashlight, and a jack if removal of the wheel is required. Depending on the type of wheels you have, you may or may not have to remove them to see the brake discs. Whether you can look through the holes in your alloy wheels or you must remove the wheel, you should be able to see the shiny disc that touches the brake pad.
Your brake discs may have shallow circular lines on them; that is normal wear. Brake discs often wear with normal friction from the brake pad; you should be able to distinguish these shallow grooves as they will be regular in shape and thickness. However, the brake discs should not be pitted or have obvious rough spots. If this has happened, you may have noticed a “gripping” sensation on your brakes when you apply them, as well. If your discs are obviously damaged, they should be replaced. Always replace brake pads in pairs, front and back; if you only replace one, you run the risk of having your brakes operate differently on each side, which can pose a safety hazard as well as causing undue stress on your autombile. When brake discs are replaced, they will take a short while to adjust and begin to wear, so drive carefully for the first few weeks; avoid sudden stops if possible.
Next you can check your brake pads. There is not much to check here except the thickness of the pads. Look up at the top of the discs; you may have to crane around a little to see the pads. If the pads have worn to 1/8 of an inch or less in thickness, it is time to replace them. You may also hear a slight squealing noise when the brakes are applied if the pads have worn away to a dangerous thinness. Because the noise is slight at first, many people ignore it; this can be very dangerous and may require replacement of your discs if it is not attended to quickly. Brake pads should also always be replaced in pairs to avoid uneven wear and problems with your braking ability.
It does not hurt, while you are inspecting your brake pads and discs, to take a look at your brake lines as well. There are two: a soft rubber line and a hard metal line. If the rubber is hard or perhaps cracked, or if the metal is corroded, it is important to replace the lines as soon as possible. Leaking brake fluid may cause a dangerous drop in your ability to break; at the very least, it will make breaking more difficult. Corrosion of the metal lines is common in areas of high salt water content, such as the coast or on snowy roads.
Remember that your brakes are too important to leave to chance–check them twice yearly and have a qualified mechanic replace the parts when necessary.